This invention relates to production of an evaporated milk product containing fats.
Evaporated milk or cream is prepared from whole milk or cream by partial removal of the water which it contains. The effect of concentration is to bring the fat globules together which can produce a raising of the fats during storage. Finally, since evaporated milk is intended for prolonged storage, it has to be sterilized.
When sterilization is carried out by a thermal preserving treatment after packing, for example in cans, there is an increased risk of destabilization of the liquid phase by heat due to the disturbance of the caseinate/calcium phosphate system after concentration. In storage, the milk thus treated can thicken and then gel. A standard method of overcoming this particular disadvantage is to add stabilizing salts such as, for example, disodium phosphate or trisodium citrate. However, these additives are being increasingly opposed by food legislation.
An alternative is the aseptic packing of evaporated milk which has been sterilized in-line, for example by the ultra-high temperature or high temperature/short time method. U.S. Pat. No. 2,886,450, for example, describes a process for the production of evaporated milk sterilized by the high temperature/short time method, in which the stability of the product in storage is improved by subjecting it to heat treatment and homogenization. However, this method does not prevent gel formation in the event of prolonged storage.